Scientists Turn Nuclear Waste Into Long-Lived Diamond Batteries

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Scientists
have figured out how to use nuclear waste as an energy source, converting
radioactive gas into artificial diamonds that could be used as batteries.

These
diamonds, which are able to generate their own electrical current, could
potentially provide a power source for thousands of years, due to the
longstanding half-life of the radioactive substances they're made from.

"There
are no moving parts involved, no emissions generated, and no maintenance
required, just direct electricity generation, by encapsulating radioactive
material inside diamonds, we turn a long-term problem of nuclear waste into a
nuclear-powered battery and a long-term supply of clean energy." says
geochemist Tom Scott from the University of Bristol in the UK.

Scott's
team has so far demonstrated a prototype diamond battery that uses an unstable
isotope of nickel (nickel–63)
as its radiation source. Nickel 63 has a half-life of approximately 100 years,
meaning the researchers' prototype device would still hold about 50 percent of
its 'charge' in 100 years' time.

But
the scientists say there's an even better source they could work with – and
doing so would end up providing a solution for the UK's massive stockpiles of
nuclear waste. The first generation of Magnox nuclear reactors in
the UK produced during the 1950s through to the 1970s used graphite blocks to
help sustain the nuclear reactions, but the technique comes at a cost.

During
the process, the graphite blocks themselves become radioactive, generating an
unstable carbon isotope, carbon–14.
The last of these Magnox reactors was retired
in 2015, but after decades of nuclear power generation, there's an awful
lot of waste byproduct left over, with almost 95,000
tonnes of these graphite blocks needing to be safely stored and
monitored while they remain radioactive and that could be a pretty long time,
given that carbon–14 has a half-life of about 5,730 years.

While
that means carbon–14 has to be stored for an extremely long time, it also means
the material could make for some amazingly long-lasting batteries – if it can
be repurposed into the diamond structure, like the team did with nickel–63.

"Carbon–14
was chosen as a source material because it emits a short-range radiation, which
is quickly absorbed by any solid material, this would make it dangerous to
ingest or touch with your naked skin, but safely held within diamond, no
short-range radiation can escape. In fact, diamond is the hardest substance
known to man, there is literally nothing we could use that could offer more
protection." says one
of the researchers, Neil Fox.

The
team shared details of their work at an "Ideas
to change the world" lecture at the University of Bristol last week,
but haven't published their research as yet, so we'll have to wait and see to
find out how viable their carbon–14 batteries really could be. According to the
researchers, carbon–14 batteries would only be good for low-power applications
– but their endurance would be on a whole different scale.

"An
alkaline AA battery weighs about 20 grams, has an energy density storage rating
of 700 Joules/gram, and [uses] up this energy if operated continuously for
about 24 hours, a diamond beta-battery containing 1 gram of C14 will deliver 15
Joules per day, and will continue to produce this level of output for 5,730
years — so its total energy storage rating is 2.7 TeraJ." Scott told Luke
Dormehl at Digital
Trends.

That
level of output could make the diamond batteries useful "in situations
where it is not feasible to charge or replace conventional batteries",
Scott said in a press
release.

"Obvious
applications would be in low-power electrical devices where long life of the
energy source is needed, such as pacemakers, satellites, high-altitude drones
or even spacecraft."

It's
early days yet, but what's exciting about this research is that it could
provide a useful purpose for a huge amount of radioactive waste, in addition to
giving us such amazing battery life.

"This
is a great example of where the UK could literally make value from waste,"
Scott told Digital
Trends.